add vty logp command to echo on all log targets

When reading SUT logs resulting from TTCN3 runs, it can be hard to figure out
which log section corresponds to which test code. Add a 'logp' command on VIEW
and ENABLE nodes that simply echos an arbitrary message on log output, useful
to set markers / explanations from the TTCN3 code, which then appear in all log
outputs and can make it trivial to figure out which log section is interesting.

	logging_vty_test# logp lglobal notice This is the log message
	DLGLOBAL NOTICE This is the log message

From TTCN3, could be used like this, e.g. in BSC_Tests.ttcn:

	private function f_logp(charstring log_msg) runs on MSC_ConnHdlr
	{
		// log on TTCN3 log output
	        log(log_msg);
		// log in stderr log
	        f_vty_transceive(BSCVTY, "logp lglobal notice " & log_msg);
	}

	...

	f_logp("f_probe_for_handover(" & log_label & "): Ending the test: Handover Failure stops the procedure.");

Change-Id: Ife5dc8999174c74e0d133729284fe526d6eaf8d9

src/vty/logging_vty.c

@@ -991,6 +991,44 @@ void logging_vty_add_deprecated_subsys(void *ctx, const char *name)
 	install_element(CFG_LOG_NODE, cmd);
 }
 
+/* logp (<categories>) (debug|...|fatal) .LOGMESSAGE*/
+DEFUN(vty_logp,
+      vty_logp_cmd,
+      NULL, /* cmdstr is dynamically set in gen_vty_logp_cmd_strs(). */
+      NULL) /* same thing for helpstr. */
+{
+	int category = log_parse_category(argv[0]);
+	int level = log_parse_level(argv[1]);
+	char *str = argv_concat(argv, argc, 2);
+	LOGP(category, level, "%s\n", str);
+	return CMD_SUCCESS;
+}
+
+static void gen_vty_logp_cmd_strs(struct cmd_element *cmd)
+{
+	char *cmd_str = NULL;
+	char *doc_str = NULL;
+
+	assert_loginfo(__func__);
+
+	OSMO_ASSERT(cmd->string == NULL);
+	OSMO_ASSERT(cmd->doc == NULL);
+
+	osmo_talloc_asprintf(tall_log_ctx, cmd_str, "logp (");
+	osmo_talloc_asprintf(tall_log_ctx, doc_str,
+			     "Print a message on all log outputs; useful for placing markers in test logs\n");
+	add_category_strings(&cmd_str, &doc_str, osmo_log_info);
+	osmo_talloc_asprintf(tall_log_ctx, cmd_str, ") %s", LOG_LEVEL_ARGS);
+	osmo_talloc_asprintf(tall_log_ctx, doc_str, "%s", LOG_LEVEL_STRS);
+
+	osmo_talloc_asprintf(tall_log_ctx, cmd_str, " .LOGMESSAGE");
+	osmo_talloc_asprintf(tall_log_ctx, doc_str,
+			     "Arbitrary message to log on given category and log level\n");
+
+	cmd->string = cmd_str;
+	cmd->doc = doc_str;
+}
+
 /*! Register logging related commands to the VTY. Call this once from
  *  your application if you want to support those commands. */
 void logging_vty_add_cmds()
@@ -1026,6 +1064,9 @@ void logging_vty_add_cmds()
 	install_element_ve(&show_logging_vty_cmd);
 	install_element_ve(&show_alarms_cmd);
 
+	gen_vty_logp_cmd_strs(&vty_logp_cmd);
+	install_element_ve(&vty_logp_cmd);
+
 	install_node(&cfg_log_node, config_write_log);
 	install_element(CFG_LOG_NODE, &logging_fltr_all_cmd);
 	install_element(CFG_LOG_NODE, &logging_use_clr_cmd);

tests/logging/logging_vty_test.vty

@@ -468,3 +468,56 @@ DCCC FATAL Log message for DCCC on level LOGL_FATAL
 DDDDD ERROR Log message for DDDDD on level LOGL_ERROR
 DDDDD FATAL Log message for DDDDD on level LOGL_FATAL
 DEEE FATAL Log message for DEEE on level LOGL_FATAL
+
+logging_vty_test# list
+...
+  logp (aa|bb|ccc|dddd|eee|lglobal|llapd|linp|lmux|lmi|lmib|lsms|lctrl|lgtp|lstats|lgsup|loap|lss7|lsccp|lsua|lm3ua|lmgcp|ljibuf|lrspro) (debug|info|notice|error|fatal) .LOGMESSAGE
+...
+
+logging_vty_test# logp?
+  logp  Print a message on all log outputs; useful for placing markers in test logs
+
+logging_vty_test# logp ?
+  aa       Antropomorphic Armadillos (AA)
+  bb       Bidirectional Breadspread (BB)
+  ccc      Chaos Communication Congress (CCC)
+  dddd     Dehydrated Dribbling Duck Dunkers (DDDD)
+  eee      Exhaustive Entropy Extraction (EEE)
+  lglobal  Library-internal global log family
+  llapd    LAPD in libosmogsm
+  linp     A-bis Intput Subsystem
+  lmux     A-bis B-Subchannel TRAU Frame Multiplex
+  lmi      A-bis Input Driver for Signalling
+  lmib     A-bis Input Driver for B-Channels (voice)
+  lsms     Layer3 Short Message Service (SMS)
+  lctrl    Control Interface
+  lgtp     GPRS GTP library
+  lstats   Statistics messages and logging
+  lgsup    Generic Subscriber Update Protocol
+  loap     Osmocom Authentication Protocol
+  lss7     libosmo-sigtran Signalling System 7
+  lsccp    libosmo-sigtran SCCP Implementation
+  lsua     libosmo-sigtran SCCP User Adaptation
+  lm3ua    libosmo-sigtran MTP3 User Adaptation
+  lmgcp    libosmo-mgcp Media Gateway Control Protocol
+  ljibuf   libosmo-netif Jitter Buffer
+  lrspro   Remote SIM protocol
+
+logging_vty_test# logp lglobal ?
+  debug   Log debug messages and higher levels
+  info    Log informational messages and higher levels
+  notice  Log noticeable messages and higher levels
+  error   Log error messages and higher levels
+  fatal   Log only fatal messages
+
+logging_vty_test# logp lglobal info ?
+  LOGMESSAGE  Arbitrary message to log on given category and log level
+
+logging_vty_test# logging level set-all notice
+
+logging_vty_test# logp aa error This is the log message
+DAA ERROR This is the log message
+
+logging_vty_test# logp lglobal debug This log message is not echoed
+logging_vty_test# logp lglobal notice This log message is echoed
+DLGLOBAL NOTICE This log message is echoed